In: Statistics and Probability
10. The data below shows the high temperatures and the times (in minutes) runners who won a marathon. Construct a scatterplot, find the value of the linear correlation coefficient r, and find the P-value using a=0.05. Is there sufficient evidence to conclude that there is a linear correlation between temperature and winning times?
Temperature_(x) Time_(y)
56 148.824
60 145.072
45 144.768
63 148.851
70 148.546
74 148.019
52 147.065
57 146.845
What are the null and alternative hypotheses?
Construct the scatterplot.
The linear correlation coefficient r is _____
(Round to three decimal places as needed.)
The test statistic t is _____
(Round to three decimal places as needed.)
The P-value is ______
(Round to three decimal places as needed.)
Because the P-value is (Less/greater) than the significance level 0.05, there (is not/ is) sufficient evidence to support the claim that there is a linear correlation between between temperature and winning times for a significance level of alphaequals0.05.
Does it appear that winning times are affected by temperature?
No, because there is not a linear correlation between the two variables.
Yes, because there is a linear correlation between the two variables.
Yes, because there is not a linear correlation between the two variables.
No, because there is a linear correlation between the two variables.
Sol:
perform hypothesis test for correlation in R
Rcode is
Temperature_x <- c(56,60,45,63,70,74,52,57)
Time_y <- c(148.824,145.072,144.768,148.851,148.546, 148.019,
147.065,146.845)
plot(Temperature_x,Time_y)
cor.test(Temperature_x,Time_y)
null and alternative hypotheses
Ho:
Ha:
Construct the scatterplot.
The linear correlation coefficient r is
r=0.583
The test statistic t is _
t=1.756
p=0.13
Because the P-value is (greater) than the significance level there (is not) sufficient evidence to support the claim that there is a linear correlation between between temperature and winning times for a significance level of alpha equals 0.05.
Does it appear that winning times are affected by temperature?
No, because there is not a linear correlation between the two variables.